Don't install/update go-bindata from //go:generate

Instead, add build instructions to the README.

README.md

@@ -2,6 +2,12 @@
 
 A URL shortener and (maybe) a pastebin server for our #ru community.
 
+## Build instructions
+
+- `go get -u github.com/go-bindata/go-bindata/...`
+- `go generate ./...`
+- `go build ./cmd/rushlink`
+
 ## Libraries
 
 Use standard-Go-libraries if the job can be done with those. As of now, these